Light Fidelity Research Articles

Indoor Positioning by Weighted Fuzzy Matching in Lifi Based Hospital Ward Environment

Core technologies of the fourth industrial revolution include AI (Artificial Intelligence), IoT (Internet of Things), and Big Data. The field of effective use of these technologies is the field of navigation. However, in indoor navigation, the accuracy is very low due to objects and walls placed in various positions. In this paper, we propose an indoor location tracking technology based on LiFi (Light Fidelity) communication to determine the exact location of a user using location tracking technology and communication technology. First of all, the fingerprinting database is constructed by measuring the CIR (Channel Impulse Response) value of each SP (Sample Point) using the fingerprinting technique. Then we use the Weighted Fuzzy Matching Algorithm to track the user’s location. The simulation results show that the performance of the LiFi environment is superior to that of the WiFi (Wireless Fidelity) environment.

Li-Fi Based Automated Patient Healthcare Monitoring System

Context: Now a days, patient healthcare monitoring systems have realized lots of consideration. This monitoring system repeatedly peer the patient health for the earlier recognition of any physical fall in health. In previous days, Wi-Fi technology was used to transmit the data regarding patient health which cause some health disorders due to its harmful radio waves. To overcome this hazardous problem, Li-Fi (Light Fidelity) is proposed which has no harmful radiation effect with fast and secure communication than Wi-Fi. For more secure, bastion algorithm is used to make the data more immune to attacks by the encryption of data using block cipher encryption and proficient linear post processing to the ciphertext. In the proposed work, the data’s are obtained using Arduino and then the statistical data’s are manipulated using deep learning algorithms for sending the emergency alert to the doctor.

Indoor Navigation System for Vision Impairment People through Visible Light Communications

Indoor navigation is opportune for everyone, and it is particularly requisite for the visually impaired. The paper proposes an indoor navigation system for the Visually Impaired to attain audio output through visible light communications. The transmission of data occurs after identifying the person who has entered the room and the technology light fidelity is used for presenting information to the user. Light fidelity technology is used by the proposed system for the wider range of transmission of data. The usage of visible light for transmitting the data encompasses a wide variety of advantages and eliminates most problems of communication caused by the electromagnetic waves outside the visible spectrum. Light fidelity technology is an evolving branch of Optical Wireless Communication and can be beneficial in coming years for indoor communication because it can afford higher data rate transmission along with the capability to utilize additional users since it uses a broader spectrum bandwidth. The main idea of our project is to create internal navigation system by using Arduino software and Arduino hardware. The transmission of data can act as transceiver, where LED and solar cell are used as the medium to transmit and receive the data.

Light Fidelity (Li - Fi) Access Point Selection for Heterogeneous Network with Non Overlapping Li - Fi Access Points

Data transmission is a part of our life in today’s scenario. Data communication can be carried out by wired technology and wireless technology. Radio frequency is a part of the electromagnetic spectrum, which is used for wireless communication. Many technologies are used for wireless communication such as Wi-Fi, Blue Tooth, Ad-hoc, and etc. These are all transmitting data through radio spectrum for short distance. New technology called as Li-Fi (Light-Fidelity) is going to be a major wireless communication technology in future. In the proposed system a heterogeneous network has been consider as a system model. Li-Fi technology is having the capacity of low coverage area. So, non movable wireless devices are getting better usage of Li-Fi technology in an indoor environment. For mobile devices need more number of Li-Fi access points. When the user moves from one access point to another access point covering range, the service should be continued without break. System handover is a major issue in the Li-Fi technology. If the user goes out of the range of light emission area, then the user can get the service through Wi-Fi access point. Proposed system focusing on the handover process based on the measured handover efficiency value. Data transmission can be disturbed due to some power failure or LED fault. In this situation immediately the entire load should be handled by the Wi-Fi access point. In such a situation data rate is coming down than the threshold value. So handover process will be handled by the common controller. Data rate is observed when the number of user increased and for variation in channel gain and the simulation results are analysed.

Design and Implementation of MPVLC Li-Fi Model for End-To-End Wireless Data Transmission

Li-Fi system is a recent and brilliant technology which is utilized visible light as a medium for multimedia data transmission. In Li-Fi communication system, transfers data in the form of light signals as an alternative of Wi-Fi. The Li-Fi technology supports transmission of multimedia data in the way of light particles by sending the multimedia data via LED bulbs that make changes in faster transmission. The Li-Fi with hardware and software model creation with many parameters that must be considered while implementing a Li-Fi based transmission system prototype which is high data rate, distance and the LOS. These parameters are taken for major component when modelling a Light Fidelity system. The main problems in the implementation of an improved data rate at low network coverage and powerless location multi point VLC system and solar component are the range and cost effective model. The VLC source component and destination component must be compatible for high data rate. The conventional lighting technique in communication feels from intrusion and maximum delay possibilities. Solution for the above light based transmission problems in implementation; VLC is a preferred communication model because of its maximum throughput and secure transmission from light particles. The proposed Multi Point Visible Light Communication Li-Fi model provides high-speed communication to achieve better capacity, efficiency, and availability at low network coverage than existing lighting technology.

Load Balancing for Hybrid LiFi and WiFi Networks: To Tackle User Mobility and Light-Path Blockage

Combining the high-speed data transmission of light fidelity (LiFi) and the ubiquitous coverage of wireless fidelity (WiFi), hybrid LiFi and WiFi networks (HLWNets) are recently proposed to improve the system capacity of indoor wireless communications. Meanwhile, load balancing becomes a challenging issue due to a complete overlap between the coverage areas of LiFi and WiFi. User mobility and light-path blockages further complicate the process of load balancing, since the decision for a horizontal or a vertical handover in a mobile environment with ultra-small cells is non-trivial. These issues are managed separately in most conventional methods, which might cause frequent handovers and compromise throughput. A few studies address these issues jointly for selecting access points at each time instant but require excessive computational complexity. In this paper, a joint optimisation problem is formulated to determine a network-level selection for each user over a period of time. A novel algorithm based on fuzzy logic is also proposed to reduce the computational complexity that is required to solve the optimisation problem. Results show that compared to the conventional method, the proposed approach can improve system throughput by up to 68%, while achieving very low computational complexity.

Handoff strategies between wireless fidelity to light fidelity systems for improving video streaming in high‐speed vehicular networks

SummaryRecent times witness heavy usage of high‐speed vehicles specially trains commuting long distances. Managing connectivity both indoor and outdoor for these vehicular networks is inevitable. Practically, the concept of wireless fidelity (WiFi) proves to be very fluctuating for the indoor users travelling in high‐speed vehicles as it operates under radio frequencies in the frequency spectrum, and handoff becomes mandatory as the user is mobile. With the introduction of light fidelity (LiFi), indoor connectivity between the mobile terminals is improved as the conversation is through light emitting diodes (LEDs) and photo detectors, which act as transmitters and receivers, respectively. Usage of LiFi in the high‐speed vehicular networks also nullifies the repercussions generated by using WiFi's highly radiated electro magnetic (EM) waves. The work proposes the use of LiFi in high‐speed rail networks for passengers streaming of videos. Travelers in train can access internet using LiFi, which uses ultra asymmetrically and symmetrically clipping optical (ASCO)–orthogonal frequency division multiplexing (OFDM) (UASCO‐OFDM) as its modulation technique. A proxy server is deployed to enhance video streaming. Furthermore, the travelers using internet need handoff in case of change in connectivity between access points (APs) of WiFi and LiFi for both outdoor and indoor, respectively. The work emphasizes on handoff based on the estimation of signal to interference ratio (SIR) followed by the combination of grey system. The performance analysis of the proposed system shows improvements in handoff probability, average delay, and spectral efficiency of modulation technique when compared to the existing literature.

Measuring Contention and Congestion on Ad-Hoc Multicast Network Towards Satellite on Ka-Band and LiFi Communication Under Tropical Environment Region

Diversified interest in the low-cost broadband satellite has overgrown to support a wide range of services in the satellite network. There is a need to explore alternative parts of optical communication towards Light Fidelity (LiFi) to offload the overcrowded radio frequency segments and improve the overall throughput. Ad hoc networks are the most suitable solution to provide a non-trivial challenge towards system design due to efficiency and quality of service (QoS). Both contention and congestion issues can severely affect the performance of a multicast network where video streaming becomes part of the day-to-day life. In this paper, we present network congestion characterization related to LiFi and High Throughput Satellite (HTS) under the Ka-band modulation schemes during adverse weather conditions in the tropical region. The heterogeneous network performance presented in this paper comprehensively provides systematic information for Satellite communication (SatCom) & LiFi and optimization of throughput by reducing network contention ratio. The measurement results have shown that when Deep Packet Inspection (DPI) policy is applied, an improvement of 80.26% in the packet delivery ratio is achieved as compared when without a DPI policy. However, using an on-premise Software-defined-wide access network (SD-WAN) alone provides 58.20% improvement in the overall network system. As a result, DPI provides a well managed QoS approach to manage the entire hybrid network, mainly in the tropical environment region.

Li-Fi: A Revolution in Wireless Networking

In this paper, the concept and theories of LiFi & VLC (Visible Light Communication) are well explained. Visible light being safe to use for wireless access in such affected environments, also provides illumination. In addition with the misconceptions about LiFi are revealed and also the scope of LiFi in industries and technology are illustrated. To minimize the network traffic, Light Fidelity (LiFi) provides an effective solution to the issues of wireless communication. Since working operations are controlled, lights become LiFi attocells resulting in enhanced wireless capacity for the Internet-of-Things (IoT), 5G and beyond. The architecture of LiFi access point that implements OFDM is investigated. Our detailed study on LiFi can show that this technology can be the pervasive network in future and can create a revolution in telecommunication.

Optical Wireless Hybrid Networks: Trends, Opportunities, Challenges, and Research Directions

Optical wireless communication (OWC) is an excellent complementary solution to its radio frequency (RF) counterpart. OWC technologies have been demonstrated to be able to support high traffic generated by massive connectivity of the Internet of Things (IoT) and upcoming 5th generation (5G) wireless communication systems. As the characteristics of OWC and RF are complementary, a combined application is regarded as a promising approach to support 5G and beyond communication systems. Hybrid RF/optical and optical/optical wireless systems offer an excellent solution for recovering the limitations of individual systems as well as for providing positive features of each of the technologies. An RF/optical wireless hybrid system consists both RF and optical-based wireless technologies, whereas an optical/optical wireless hybrid system consists two or more types of OWC technologies. The co-deployment of wireless systems can improve system performance in terms of throughput, reliability, and energy efficiency of individual networks. This study surveys the state of the art and key research directions regarding optical wireless hybrid networks, being the first extensive survey dedicated to this topic. We provide a technology overview of existing literature on optical wireless hybrid networks, such as RF/optical and optical/optical systems. We consider the RF-based macrocell, small cell, wireless fidelity, and Bluetooth, as well as optical-based visible light communication, light fidelity, optical camera communication, and free-space optical communication technologies for different combinations of hybrid systems. Moreover, we consider underwater acoustic communication for hybrid acoustic/optical systems. The opportunities brought by hybrid systems are presented in detail. We outline important challenges that need to be addressed for successful deployment of optical wireless hybrid network systems for 5G and IoT paradigms.

DESIGN OF A LI-FI TRANSCEIVER .

The latest uproar in this era is about a technology termed as Light Fidelity or more commonly known as Li-Fi. There are currently two trends being seen: First, the extension or enrichment of wireless services and other being in-creased in user demand for these services, but the available RF spectrum for usage is very limited. So the new technology of Li-Fi came into picture, which uses visible light as a source of communication. Li-Fi is the most recent de-velopment which is resourceful. In this technology, LEDs are used to transmit data in the visible light spectrum. This technology can be compared with that of Wi-Fi and offers advantages like increased accessible spectrum, efficiency, security, low latency and much higher speed. This research paper aims at de-signing a Li-Fi transceiver using Arduino that is able to transmit digital data. The hardware has been designed using Eagle CAD (version 7.1.0) tool and Proteus design tool (version 8). The software coding is done by using Java (version 8). Successful transmission and reception of text, image and video signals is carried out on the transceiver. Hence this research work gives an innovative way of designing a transceiver which works by using off the shelf low cost components and using visible light spectrum.

Software-Defined Networking-Enabled Heterogeneous Wireless Networks and Applications Convergence

A software-defined networking (SDN) architecture is capable of integrating all radio frequency and optical wireless small cell networks (e.g. fifth generation (5G), long-term evolution (LTE) femtocell, wireless fidelity (WiFi), light fidelity (LiFi)) in one network domain. This paper considers a SDN-enabled heterogeneous network (HetNet) comprised of LiFi, LTE femtocell and WiFi access points (APs). The HetNet control plane maintains the state of the network topology and wireless resources, which can support the development of intelligent service provisioning and efficient data communications in x generation (xG) wireless networks. The SDN applications use the network state to provide services in the data plane. However, when the state of network and wireless resources constantly changes, the SDN applications cannot provide reliable and guaranteed services to the wireless user equipments. This paper develops a queuing theoretic framework, which provides a performance evaluation for the SDN-enabled HetNet and applications convergence. A traffic engineering (TE) scheme is developed to support dynamic agnostic downlink flows routing to APs and differentiated granular services across the HetNet. Network and user centric policies are developed to make applications aware of network resource availability on the northbound and southbound interfaces of a SDN controller. Numerical models are introduced to study the impact of the computation and communication resources of northbound and southbound interfaces on the SDN-enabled HetNet scalability and the quality-of-service (QoS) guarantee of applications. Also, simulation scenarios are conducted to evaluate the performance of the TE scheme in provisioning effective and reliable services for subscribers.

Análisis de desempeño a nivel de simulación de un sistema de comunicaciones Li-Fi para la transmisión de datos a alta velocidad

Los altos requerimientos inalámbricos en acceso, capacidad y seguridad que demanda la sociedad actual junto con la gran congestión del espectro radioeléctrico ha llevado a buscar nuevas soluciones tecnologías como es la Fidelidad de la Luz (Li-Fi). Este artículo presenta el diseño e implementación de un sistema de comunicaciones Li-Fi dentro de un ambiente indoor utilizado la técnica de modulación OFDM óptica con recorte asimétrico (ACO-OFDM) a través del software MATLAB. El desempeño del sistema se analiza en términos de la tasa de error de bit (BER) y la relación energía de bit a potencia de ruido (Eb/No) teniendo en cuenta la posición del receptor, orden de modulación QAM y velocidad de transmisión. Los resultados muestran que el desempeño del sistema depende directamente de la posición del receptor, además para altas tasas de transmisión el efecto multitrayectoria degrada el desempeño del sistema.

Constellation Design for Single Photodetector Based CSK With Probabilistic Shaping and White Color Balance

Research and development of Li-Fi (Light Fidelity) in Internet-of-things (IoT) has created significant interest among researchers. The low-cost version of standard color shift keying (CSK) modulation scheme having single photodetector (PD) at the receiver can become an alternative to on-off keying (OOK) in IoT sensor networks as an M -ary CSK modulation scheme provides log 2 M times more data rate than that of OOK. This work revolves around optimizing the constellation points of single PD based CSK (CSK-1PD) to achieve a more power-efficient modulation scheme. The optimization has been done with and without average white tone constraint for uniform and non-uniform (exponential, Maxwell-Boltzmann, Pareto) source distributions. The constellation design strategy is based on maximizing the minimum distance among the differently distributed symbols. In the case of non-uniform distributions, the constellations points have been optimized by geometrically shaping the points based on their probabilistic shaping (PS). The optimized constellation points (OCPs) of CSK-1PD without white tone constraint provide higher signal-to-noise ratio (SNR) gain at forward error correction (FEC) limit symbol error rate (SER) as compared with strict white tone constraint. Further, the strict white tone constraint has been relaxed by considering the whole white light region in the CIE 1931 chromaticity diagram as white tone. The OCPs for uniform data with relaxed white tone constraint achieves SNR gain similar to without white tone constraint. However, for probabilistically shaped symbols, the SNR gain achieved from OCPs improves from strict white tone constraint but remains less than the without white tone constraint. A novel method to utilize an additional RGB LED at the transmitter side has been proposed and designed to maintain any white tone light in the white light region without degrading the maximum achieved SNR gain.

Load Balancing Scheme in Hybrid WiGig/LiFi Network

Recently, Light fidelity (LiFi) is proposed as a high-speed wireless communication technology. A LiFi access point provides the service in an area of a few square meters known as LiFi attocells. Therefore, by utilizing frequency reuse, LiFi networks provide a high spatial spectral efficiency. Unfortunately, beside to uplink and mobility problems, the LiFi networks suffer more difficulties with increasing of the number of mobile devices. As a solution, hybrid LiFi and radio frequency (RF) networks are proposed. In this article, a hybrid network, that combines LiFi with RF Wireless Gigabit Alliance (WiGig) networks, is proposed. The WiGig access points will provide gigabit-per-second data rates as a result of the availability of large bandwidth at the millimeter wave (mmWave) frequency ranges. Such hybrid networks need an efficient load balancing (LB) scheme. In this article, two modified versions of the separate optimization algorithm (SOA) are proposed; Assign WiGig First SOA (AWFS) algorithm and Consecutive Assign WiGig First SOA (CAWFS) algorithm. The simulation results show that the two proposed algorithms offer better achievable data rates and outage probability performances compared with the SOA algorithm.

Photovoltaic Solar Cells for Outdoor LiFi Communications

Increasing demand of wireless devices contributes to radiofrequency (RF) congestion. Light Fidelity (LiFi) promises to be an interesting alternative by using the visible part of the electromagnetic spectrum instead of the RF part as nearly all existing wireless transmission systems do. A basic LiFi system is composed of one intensity-controlled light-emitting diode (LED) and one receiver device sensitive to very high-frequency (thus invisible to human sight) modulations of the luminous intensity. In most cases, the photoreceptor is a silicon photodiode of PIN (P-type intrinsic N-type) or APD (Avalanche photodiode) conception. Recently, a few studies suggest that photovoltaic (PV) modules could be used to implement outdoor LiFi transmissions, i.e., under direct sunlight exposure. In this paper, we propose to compare the behavior of a PV module and a commercial APD-based photodetector (without any optical lens or colored filter) for experimental LiFi transmissions on both indoor and outdoor conditions. The performance of the two solutions is quantified in terms of various frequency responses like attenuation, signal-to-noise ratio, or bit-error rate. The results show that, while the photodiode exhibits very good performance in indoor conditions, its frequency response is rapidly deteriorating when a sunlight exposure of more than 200 W/m $^2$ is superimposed over the LiFi signal. We demonstrate that a PV module in $V_{oc}$ (open-circuit voltage) condition still operates a LiFi transmission under additional solar illumination.

Reinforcement Learning Based Load Balancing for Hybrid LiFi WiFi Networks

Light fidelity (LiFi) is an emerging communication technology, which utilizes the light-emitting diodes (LEDs) for high-speed wireless communications. Due to its huge unlicensed bandwidth, LiFi is capable of supporting high data rates. The quality of the LiFi channel fluctuates across the room due to interference, reflection from walls or blockage. On the other hand, WiFi is another wireless communication technology that is capable of providing moderate data rates with ubiquitous coverage. As the electromagnetic spectrum of LiFi does not overlap with WiFi, both of them can coexist to form a hybrid LiFi and WiFi network for seamless and high-throughput connectivity. The performance of a hybrid system significantly depends upon the access point (AP) assignment and resource allocation strategies. In this paper, a downlink hybrid system with one WiFi AP and four LiFi APs is considered, and a reinforcement learning (RL) algorithm is implemented in order to determine an optimal AP assignment strategy, which maximizes the long-term system throughput while ensuring the required users fairness and satisfaction. Furthermore, two different scenarios based on the random waypoint model with uniform and non-uniform distribution of users have been studied. The performance of the proposed system is compared against state-of-the-art benchmark approaches e.g., signal strength strategy (SSS), exhaustive search, and an iterative optimization method. The results are reported in terms of the average system throughput, user satisfaction, fairness, and capacity outage probability. It is shown that the proposed RL method performs closer to the exhaustive search scheme at fairly low complexity. The RL method also outperforms the SSS scheme and the iterative algorithm in most scenarios.

Client-Centric Access Device Selection for Heterogeneous QoS Requirements in Beyond 5G IoT Networks

The expected manifolds increase in the traffic and the massive number of connected Internet of Things (IoT) devices would be a challenge to ensure a certain Quality of Service (QoS) in Beyond 5G (B5G) networks. Due to the increased availability of processing and energy resources and heterogeneous QoS requirements in modern IoT nodes, a client-centric access device selection approach for QoS provisioning in multiple Radio Access Technologies (RATs) scenario is proposed in this paper. The proposed algorithm provides the ability to specify node-specific QoS requirements at each node, a better access device selection, and improved network scalability. For experimental evaluation, a hybrid indoor network consisting of Wireless Fidelity (WiFi) and Light Fidelity (LiFi) RATs has been considered. Experimental results show that the proposed technique outperforms several conventional client-based access device selection approaches by up to 32.66% in network emulation experiments and up to 50% in hardware experimentation. The contribution of this paper includes the proposed algorithm, its complexity and game-theory based convergence analyses, evaluation of the proposed algorithm using network emulation and hardware-based setups, and LiFi channel analysis. The analyses and results imply that the proposed algorithm could be utilized in next-generation IoT networks as it performs better than conventionally used access device selection techniques for QoS provisioning.

EXPLORING VISIBLE SPECTRUM: A STUDY OF LIGHT FIDELITY SYSTEM AND ITS APPLICATIONS.

This Document gives an introductory analysis of how Li-Fi technology can provide a wide range of spectrum to the user with very low interference. It also gives the details of the technology and its advantages over the contemporary Wi-Fi technology. Morever since we are using the spectrum at a rapid rate this paper also shows the potential viability of light fidelity system as a major promising source of technology for tomorrow

Interface protocol design: a communication guide for indoor FANET

The present and the future routing protocols in relation to the high throughput requirement, adaptivity to fast-changing link topology and speed makes the choice of routing protocol for unmanned aerial vehicle communication important. Due to this fact, an efficient routing protocol is highly dependent on the nature of the communication link. A flexible solution that presents these features is the use of light fidelity as a communication medium. Therefore, this paper presents the design of an interface protocol for indoor Flying Ad-hoc Network specific routing protocol using light fidelity as a communication link. The interface protocol governs communication when UAV move in a swarm. The architecture, the state machine model is discussed in this paper. Results of the design are validated via simulation using the NS3 in terms of packet delivery ratio and throughput.